Sling back chair



FIG. 1 is a front perspective view of a sling back chair showing my new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a front elevational view thereof; and,

FIG. 4 is a top plan view thereof.

The fragmented cross-hatching shown in FIGS. 1, 3 and 4 is understood to represent fabric and would be continuous throughout the circumscribed area.

The rear of the chair has not been shown and forms no part of the claimed design. 

The ornamental design for a sling back chair, as shown and described. 